Does installing solar power add to a home’s value? The answer is yes — though exactly how much has not been entirely certain as Realtors and appraisers are still learning how to properly weigh the value of renewable energy additions to a home.

Three recent California studies have found that solar photovoltaic arrays added close to their exact retail cost to a home’s value, even years after the investment started to pay for itself.

Preliminary evidence in the New England market appears to confirm the California results, though the ability to monetize how much solar PV systems add to a home’s value is still developing here. But, when it comes time to sell a home, most homeowners find that their solar PV system adds as much to their home’s value as what they originally paid for it.

The urge to install solar power typically has been an environmental motivation. The economics weren’t there, says Fred Greenhalgh, online marketing manager and sales associate at ReVision Energy. “Now, the economics have changed. To people who wouldn’t even have thought about it, now it makes sense. We’ve reached a tipping point and have seen huge growth. Solar protects you against cost of traditional energy.”